New "Tornado" sound sample ....

[96ecss]

Sounds great.

[MartyMart]

Gauss,
R4 off Q1 source is 2k2 and C3 is 680n
R7 is 330K
R12 off the Muamp is a 330 Ohm

Sorry my schem wasn't clear enough here and there ....

MM

[gaussmarkov]

Gauss,
R4 off Q1 source is 2k2 and C3 is 680n
R7 is 330K
R12 off the Muamp is a 330 Ohm

Sorry my schem wasn't clear enough here and there ....

MM

hmm.  i don't think it was your writing.

i made the changes to the image in the original post, but added a "rev. 1" to distinguish the new image from the old one.  that seemed less likely to cause confusion and it will keep this thread tidier.

i also posted the eagle schem file and parts list in the layouts section of gaussmarkov.net.  if anyone is interested in doing a layout in eagle, they could start with that.  download the guassmarkov eagle libraries, too, so that you can easily change the pad locations of individual components. 

nice one Marty!  thanks for this.

gm

[MartyMart]

Gauss, I can't see thechanges in the posted file yet ?? .... byt thanks again

Here's some "Gain mod" and "Tone mod" ideas, perhaps you can
include them in the project, also some voltages :

Initially, I recommend building this as per the schem, fit sockets where appropriate
so you can easily try some "mods"

Tornado More Gain Mod :

Replace the 820k from the Muamp section with a lower value, 680k and 560k work well
but much lower here and you'll have "oscillation" problems !!
Also you can reduce the 680k from Q1 to a 470k for a touch more gain and reduce the 470k
after the 33n to 330k.
Try these one at a time otherwise the gain can easily get "out of control"
Re-bias the drains after doing any changes.
Voltages for Q1/Q2/Q5/Q6 drains are best between 4.5v and 5v, above 5v and the circuit will be
cleaner and have more headroom.
Q3 of the Muamp will be battery voltage and the lower fet, Q4 will ba approx 1/2 battery voltage.

Tornado Tone mods :

The tone was setup for a good "full bodied" sound without too much "flabby" low end and a crisp
top end, so change at your own risk !!
Suggestions would be :
For a thinner sound, reduce the 22n's 33n and 47n to 10n's 22n and 33n in the same order.
For a lift in bottom end, slightly increase these same caps and also change the two 680n bypass caps
to 1uf's or 2u2's
This last change will make the distortion increase too, in particular the low end distortion !

MartyMart  2007

[gaussmarkov]

you can't see the changes?  i can, and i checked that before posting.  i'm guessing that you need to refresh with your browser.

hmm.  it looks like the big version of the schem (see the link) has been reduced by photobucket. 

[MartyMart]

Hmm, I had to erase my "cache" to see the new version ??

Cheers,

MM.

[gaussmarkov]

Hmm, I had to erase my "cache" to see the new version ??

weird.  i don't know why that would be.  what browser are you using?  i was using firefox.

no takers on the eagle schem, so i took a stab at a perf layout.  Marty, if you verified the schem, then we can consider this layout verified.



26 x 17.  when i get more time, i'll make a few more adjustments and then create an image for etching a pcb with this layout.  the part list for this layout is already posted on gaussmarkov.net.

mo l8r, gm 

[John Lyons]

Say..that looks very tidy gaussmarkov! Nice work.

John

[gaussmarkov]

Say..that looks very tidy gaussmarkov! Nice work.

John

thanks, john!  i was thinking that francisco pena would've made the pot hook ups evenly spaced. 

[MartyMart]

Gauss, that looks VERY nice !!
My eyes are going wierd trying to check it, but I think it's fine
( I'm more used to vero !! )
I'll try a vero layout on monday, my "prototype" ended up VERY big, 3.5cm X 12cm !!
But I see where I can reduce it, it may well have helped me get a quiet build !

MM.

[slacker]

nice one Marty, great sound and a great name

[markm]

Say..that looks very tidy gaussmarkov! Nice work.

John

Agreed.
Nice work gm 
I'm not a big fan of heavy distortion but Hell, great sounding circuit Marty!!

[gaussmarkov]

oops.  when i created the mpf102 library component i reversed the drain and gate pins.  so Q1 is backwards.   i was afraid of that and i just rechecked.  i will post a brand new layout image this time.

Nice work gm 

thanks mark! 

[gaussmarkov]

hey, i noted the layout error in the previous post and i have revised all of the files and put them up
on gaussmarkov.net, including a pdf project file:

• 
  zipped eagle files
  
• 
  schematic image
  
• 
  layout image
  
• 
  parts list
  
• 
  300 dpi pcb image
  
• pdf project file

enjoy, gm

[John Lyons]

Very nice!
Thanks for all your work on this gaussmarkov
And thanks to marty especially for making a great sounding circuit!!!

John

[JimRayden]

I gave the layout some balls, it seemed to be a bit too flimsy.

Hope you don't mind.

---------
Jimbo

[gaussmarkov]

I gave the layout some balls, it seemed to be a bit too flimsy.

Hope you don't mind.

---------
Jimbo

  great!  i haven't been sure about the widths that i should use.  perhaps i'll go back to all the gaussmarkov.net pcb images and beef them up.  my trace widths are 024 mil.  032 or 040 instead?

cheers, gm

[JimRayden]

I live by the 50:50 rule. I try to make a trace and the spaces between them roughly equal. With the usual 2.5mm grid spacing, that makes 1.25mil perfect for my tastes.

That's roughly .05" so I guess .04" looks pretty good.

----------
Jimbo

[John Lyons]

I usually go .04 or .05 depending. Soldering and etching larger pads and traces is so much easier.
Cool!
John

[MartyMart]

GM, great stuff  ... many many thanks for making a whole project file from this

You're a true "Gent"   

As soon as someone has built one, PLEASE write a report and post it up as I'd love to hear
your thoughts .....

MM.